Electroluminescent iridium compounds with phosphinoalkoxides and phenylpyridines or phenylpyrimidines and devices made with such compounds

ABSTRACT

The present invention is generally directed to electroluminescent Ir(III) compounds with phosphinoalkoxides and phenylpyridines or phenylpyrimidines, and devices that are made with the Ir(III) compounds.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to electroluminescent complexes of iridium(III)with phenylpyridines or phenylpyrimidines, which additionally have aphosphinoalkoxide ligand. It also relates to electronic devices in whichthe active layer includes an electroluminescent Ir(III) complex.

2. Description of the Related Art

Organic electronic devices that emit light, such as light-emittingdiodes that make up displays, are present in many different kinds ofelectronic equipment. In all such devices, an organic active layer issandwiched between two electrical contact layers. At least one of theelectrical contact layers is light-transmitting so that light can passthrough the electrical contact layer. The organic active layer emitslight through the light-transmitting electrical contact layer uponapplication of electricity across the electrical contact layers.

It is well known to use organic electroluminescent compounds as theactive component in light-emitting diodes. Simple organic molecules suchas anthracene, thiadiazole derivatives, and coumarin derivatives areknown to show electroluminescence. Semiconductive conjugated polymershave also been used as electroluminescent components, as has beendisclosed in, for example, Friend et al., U.S. Pat. No. 5,247,190,Heeger et al., U.S. Pat. No. 5,408,109, and Nakano et al., PublishedEuropean Patent Application 443 861. Complexes of 8-hydroxyquinolatewith trivalent metal ions, particularly aluminum, have been extensivelyused as electroluminescent components, as has been disclosed in, forexample, Tang et al., U.S. Pat. No. 5,552,678.

Burrows and Thompson have reported that fac-tris(2-phenylpyridine)iridium can be used as the active component in organic light-emittingdevices. (Appl. Phys. Lett. 1999, 75, 4.) The performance is maximizedwhen the iridium compound is present in a host conductive material.Thompson has further reported devices in which the active layer ispoly(N-vinyl carbazole) doped withfac-tris[2-(4′,5′-difluorophenyl)pyridine-C′²,N]iridium(III). (PolymerPreprints 2000, 41(1), 770.) Additional electroluminescent devices withan active layer of polymer doped with organometallic complexes ofiridium have been described by Burrows and Thompson in published PCTapplications WO 00/70655 and WO 01/41512. Most of these complexes haveemission spectra with peaks in the green or blue-green region.

However, there is a continuing need for electroluminescent compoundshaving improved efficiency and/or having emission maxima in the blueregion of the spectrum.

SUMMARY OF THE INVENTION

The present invention is directed to an iridium compound having thefollowing Formula I:IrL^(a)L^(b)L′  (I)

where

-   -   L^(a) and L^(b) are alike or different and each of L^(a) and        L^(b) has Formula II, shown in FIG. 1, wherein:        -   R¹ through R⁸ are independently selected from hydrogen,            deuterium, alkyl, alkoxy, halogen, nitro, cyano, fluoro,            C_(n)(H+F)_(2n+1), OC_(n)(H+F)_(2n+1), and OCF₂X, where n is            an integer from 1 through 12, and X is H, Cl, or Br, and        -   A is C or N, provided that when A is N, there is no R¹; and    -   L′ is a bidentate phosphino alkoxide ligand having Formula III,        shown in FIG. 2, wherein:        -   R⁹ can be the same or different at each occurrence and is            selected from C_(m)(H+F)_(2n+1), C₆(H+F)_(p)Y_(5−p),        -   R¹⁰ can be the same or different at each occurrence and is            selected from H, F, and C_(n)(H+F)_(2n+1);        -   Y is C_(m)(H+F)_(2m+1);        -   n is an integer from 1 through 12;        -   m is 2 or 3;        -   p is 0 or an integer from 1 through 5.

In another embodiment, the present invention is directed tophosphinoalkanol precursor compounds from which the phosphinoalkoxideligands are made. The phosphinoalkanol compounds have Formula III-H,shown in FIG. 2, in which R⁹, R¹⁰, Y, n, m, and p are as defined abovefor Formula III.

In another embodiment, the present invention is directed to a processfor making a phosphinoalkanolcompound.

In another embodiment, the present invention is directed to an organicelectronic device having at least one emitting layer comprising theabove Ir(III) compound, or combinations of the above Ir(III) compounds.

As used herein, the term “compound” is intended to mean an electricallyuncharged substance made up of molecules that further consist of atoms,wherein the atoms cannot be separated by physical means. The term“ligand” is intended to mean a molecule, ion, or atom that is attachedto the coordination sphere of a metallic ion. The term “complex”, whenused as a noun, is intended to mean a compound having at least onemetallic ion and at least one ligand. The term “group” is intended tomean a part of a compound, such a substituent in an organic compound ora ligand in a complex. The phrase “adjacent to,” when used to refer tolayers in a device, does not necessarily mean that one layer isimmediately next to another layer. On the other hand, the phrase“adjacent R groups,” is used to refer to R groups that are next to eachother in a chemical formula (i.e., R groups that are on atoms joined bya bond). The term “photoactive” refers to any material that exhibitselectroluminescence and/or photosensitivity. The term “(H+F)” isintended to mean all combinations of hydrogen and fluorine, includingcompletely hydrogenated, partially fluorinated or perfluorinatedsubstituents. By “emission maximum” is meant the wavelength, innanometers, at which the maximum intensity of electroluminescence isobtained. Electroluminescence is generally measured in a diodestructure, in which the material to be tested is sandwiched between twoelectrical contact layers and a voltage is applied. The light intensityand wavelength can be measured, for example, by a photodiode and aspectrograph, respectively. In addition, the IUPAC numbering system isused throughout, where the groups from the Periodic Table are numberedfrom left to right as 1 through 18 (CRC Handbook of Chemistry andPhysics, 81^(st) Edition, 2000).

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows Formula II for phenylpyridine and phenylpyrimidine ligandsuseful in the metal complex of the invention, and Formula II-H for theligand precursor compound.

FIG. 2 shows Formula III for phosphinoalkanoxide ligands useful in themetal complex of the invention, and Formula III-H for the ligandprecursor compound.

FIG. 3 shows Equation 1 for forming the ligand precursor compound, II-H.

FIG. 4 shows Equation 2 for forming the ligand precursor compound,III-H.

FIG. 5 shows Formulae IV and V for bridged Ir dimers.

FIG. 6 is a schematic diagram of a light-emitting device (LED).

FIG. 7 is a schematic diagram of an LED testing apparatus.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The Ir(III) compounds of the invention have Formula I, as defined above.The compounds are frequently referred to as bis-cyclometalatedcomplexes. The cyclometalated complexes of the invention are neutral andnon-ionic, and can be sublimed intact. Thin films of these materialsobtained via vacuum deposition exhibit good to excellentelectroluminescent properties.

Two of the ligands in the Ir(III) compounds of the invention, arephenylpyridine or phenylpyrimidine ligands having Formula II, shown inFIG. 1. The R¹ through R⁸ groups of Formula II may be chosen fromconventional substitutents for organic compounds, such as alkyl, alkoxy,halogen, nitro, and cyano groups, as well as fluoro, fluorinated alkyland fluorinated alkoxy groups. The groups can be partially or fullyfluorinated (perfluorinated).

The precursor 2-phenylpyridines and 2-phenylpyrimidines, Formula II-H inFIG. 1, are prepared, in good to excellent yield, using the Suzukicoupling of the substituted 2-chloropyridine or 2-chloropyrimidine witharylboronic acid as described in O. Lohse, P. Thevenin, E. WaldvogelSynlett, 1999, 45–48. This reaction is illustrated for the pyridinederivative, where X and Y represent substituents, in Equation (1) shownin FIG. 3.

Examples of 2-phenylpyridine and 2-phenylpyrimidine compounds, havingFormula II-H, are given in Table 1 below:

TABLE 1 Compound A R₁ R₂ R₃ R₄ R₅ R₆ R₇ R₈ R₉ 1-a C H H CF₃ H F H H H H1-b C H H CF₃ H H CF₃ H H H 1-c C H H NO₂ H H CF₃ H H H 1-d C H H CF₃ HH F H H H 1-e C H H CF₃ H H H CH₃O H H 1-f C Cl H CF₃ H H H H H H 1-g CH H H CH₃ H H F H H 1-h N — H H H H H F H H 1-i C H H CF₃ H H H CF₃O H H1-j N — CF₃ H H F H H H H 1-k C H H CF₃ H H H F H H 1-l C CF₃ H H H H HH H H 1-m C Cl H CF₃ H H H F H H 1-n C CF₃ H H H H H F H H 1-o C CF₃ H HH H H CH₃O H H 1-p C Cl H CF₃ H H H CH₃O H H 1-q N — CF₃ H H H H F H H1-r C Cl H CF₃ H H H H H H 1-s C H H CF₃ H H H H H H 1-t C Cl H H H F HH H H 1-v C H H CF₃ H H CH₃O H H H 1-w C H CH₃O H H H H CF₃ H H 1-x C HH H H H F F H H 1-y C H H CF₃ H H F H F H 1-z C H H CF₃ H F H F H H 1-aaC H H Br H H H Br H H 1-ab C H CH₃ H H F H F H H 1-ac C H CH₃ H H H CF₃H CF₃ H 1-ad C H H CH₃ H F H F H H 1-ae C H CH₃ H H H CF₃ H H H 1-af C HH CH₃ H H CF₃ H CF₃ H 1-ag C H H H H H CF₃ H H H 1-ah C H H H H F H F HH 1-ai C H t-Bu H H F H F H H 1-aj C H t-Bu H H H CF₃ H CF₃ H 1-ak C HCH₃ H H H H CF₃ H H 1-al C H H H H CH₃O H CH₃O H Hwhere “t-Bu” represents a tertiary butyl group.

The third ligand in the Ir(III) compounds of the invention is aphosphinoalkoxide. The precursor phosphinoalkanol compounds havingFormula III-H, as shown in FIG. 2, can be prepared using knownprocedures, such as, for example, the procedure reported in Inorg. Chem.1985, v. 24, p. 3680, for1,1-bis(trifluoromethyl)-2-(diphenylphosphino)ethanol. This methodinvolves the reaction of diphenylphosphinomethyllithium withhexafluoroacetylacetone, followed by hydrolysis.

Alternatively, the phosphino alkanol compounds can be prepared using thereaction of 1,1-bis(trifluoromethyl)ethylene oxide with thecorresponding secondary phosphine (R⁹ ₂PH) or its deprotonated form as asalt ([R⁹ ₂P]M), where M is Li, Na, or K. The deprotonated form can beprepared by the treatment of the secondary phosphine with a strong base,such as BuLi or t-BuOK.

Alternatively, the phosphino alkanol compounds can be made usingdilithiated derivatives of halohydrins, which can be prepared asdescribed in J. Chem. Soc., Perkin Trans. 1, 1983, p. 3019. Thedilithio-derivative is reacted with a chlorophosphine to produce thedesired phosphinoalkanol ligand. Halohydrins are made by a variety ofliterature methods, such as ring-opening of an epoxide (also called an“oxirane”) with HHal (Hal=Cl, Br, I; see: J. Am. Chem. Soc. 1960, vol.82, p. 2288). This is particularly useful for1,1-bis(trifluoromethyl)ethylene oxide which can be prepared asdescribed in Petrov, V. A. et al., WO 00/66575, PCT/US00/11746, Chem.Abstr. 2000, 350691. In the process of the invention, a driedbromohydrin is combined with n-butyl lithium, wherein the molar ratio ofn-butyl lithium to bromohydrin is about 2. The preferred process forpreparing the phosphino alkanol comprises the steps:

(1) combining an epoxide with aqueous HBr, to form a bromohydrin;

(2) isolating the bromohydrin from step (1) and removing water;

(3) combining the dried bromohydrin from step (2) with n-butyl lithium,wherein the molar ratio of n-butyl lithium to the bromohydrin is about2;

(4) adding a chlorophosphine to the product of step (3); and

(5) adding acid to the product of step (4).

The epoxide can be substituted with groups such as alkyl, partiallyfluorinated alkyl, and perfluoroalkyl groups; preferably trifluoromethylgroups. The chlorophosphine is a chlorodialkylphosphine or achlorodiarylphosphine; preferably, chlorodiphenylphosphine. The acid canbe any Bronsted acid which will provide a proton in the last reactionstep, preferably trifluoroacetic acid. The reaction scheme isillustrated using bis(trifluoromethyl)ethylene oxide in Equation (2),shown in FIG. 4. The dilithiation of the bromohydrin deriving frombis(trifluoromethyl)ethylene oxide can be done with 2 equivalents ofBuLi within 0.5 h at −78° C. This is different from the literatureprocedure (J. Chem. Soc., Perkin Trans. 1, 1983, p. 3019) which employs1 equivalent of BuLi for 3 hours, followed by 1 equivalent of naphthyllithium for 5 hours at −78° C. Napthyl lithium is not commerciallyavailable and is more expensive to make. The process of the inventionis, in general, faster and uses readily available butyl lithium.

In the preferred phosphinoalkanol of Formula III-H, R⁹ is C₆F₅ orC₆H_(p)Y_(5−p), where Y is CF₃ and p is 3 or 4. Preferably at least oneof R¹⁰ is CF₃ and m is 2.

Examples of suitable phosphinoalkanol compounds, with the abbreviationin brackets, include:

-   1-diphenylphosphino-2-propanol [dppOH]-   1-bis(trifluoromethyl)-2-(diphenylphosphino)ethanol [PO-1H]-   1,1-bis(trifluoromethyl)-2-(bis(3′5′-ditrifluoromethylphenyl)phosphino)ethanol    [PO-2H]-   1,1-bis(trifluoromethyl)-2-(bis(4′-trifluoromethylphenyl)phosphino)ethanol    [PO-3H]-   1,1-bis(trifluoromethyl)-2-(bis(pentafluorophenyl)phosphino)ethanol    [PO-4H]    The phosphinoalkoxide ligands from the above compounds are,    respectively (abbreviations provided in brackets):-   1-diphenylphosphino-2-propoxide [dppO]-   1-bis(trifluoromethyl)-2-(diphenylphosphino)ethoxide [PO-1]-   1,1-bis(trifluoromethyl)-2-(bis(3′5′-ditrifluoromethylphenyl)phosphino)ethoxide    [PO-2]-   1,1-bis(trifluoromethyl)-2-(bis(4′-trifluoromethylphenyl)phosphino)ethoxide    [PO-3]-   1,1-bis(trifluoromethyl)-2-(bis(pentafluorophenyl)phosphino)ethoxide    [PO-4]

The iridium complexes of the invention can be prepared by firstpreparing an intermediate iridium dimer with the phenylpyridine orphenypyrimidine ligand. The dimer can be the dichloro bridged dimerhaving Formula IV, shown in FIG. 5, or the dihydroxo bridged dimerhaving Formula V, shown in FIG. 5, where:

in Formulae IV and V:

-   -   L^(a), L^(b), L^(c), and L^(d) can be the same or different from        each other and each of L^(a), L^(b), L^(c), and L^(d) has        Formula II, as defined above;

in Formula V:B═H, CH₃, or C₂H₅.

The dichloro bridged dimers having Formula IV, can generally be preparedby reacting iridium trichloride hydrate with the 2-phenylpyridine or2-phenylpyrimidine in a suitable solvent, such as 2-ethoxyethanol. Theiridium bridged dimers having Formula V, can generally be prepared byreacting iridium trichloride hydrate with the 2-phenylpyridine or2-phenylpyrimidine, and then adding NaOB. These dicyclometalatedcomplexes can be isolated and (optionally) purified before the reactionwith the phosphinoalkanols or used without isolation, as described inthe examples below. The chloro dicyclometalated complexes can react,under biphasic or homogeneous conditions, with either thephosphinoalkanols in the presence of a base, such as NaOH, or salts ofthe phosphinoalkanols. When salts of the phosphinoalkanols are used withthe dichloro bridged dimers, and also when intermediates having FormulaV are used, no additional base is required for the synthesis.

Examples of compounds having Formula I, where L^(a) is the same asL^(b), are given in Table 2 below, where R¹ through R⁸ are as shown inFormula I, and A is C.

TABLE 2 Comp. L′ R¹ R² R³ R⁴ R⁵ R⁶ R⁷ R⁸ 2-a PO-1 H CH₃ H H F H F H 2-bPO-2 H CH₃ H H F H F H 2-c PO-1 H H H H F H F H 2-d PO-2 H H H H F H F H2-e PO-1 H H H H H CF₃ H H 2-f PO-1 H CH₃ H H H CF₃ H CF₃ 2-g PO-2 H CH₃H H H CF₃ H CF₃ 2-h PO-1 H H CH₃ H F H F H 2-i PO-2 H H CH₃ H F H F H2-j PO-1 H H CF₃ H H H F H 2-k PO-1 H t-Bu H H F H F H 2-l PO-1 H t-Bu HH H CF₃ H CF₃ 2-m PO-3 H H CH₃ H F H F H 2-n PO-3 H CH₃ H H F H F H 2-oPO-1 H H H H CH₃O H CH₃O H 2-p PO-2 H H H H CH₃O H CH₃O H 2-q PO-1 H CH₃H H H CF₃ H H 2-r PO-2 H CH₃ H H H CF₃ H H 2-s PO-1 H CH₃ H H H H CF₃ H2-t PO-4 H CH₃ H H H CF₃ H CF₃ 2-u PO-4 H CH₃ H H F H F H 2-v PO-2 H H HH H H H H

where “t-Bu” represents a tertiary butyl group.

Electronic Device

The present invention also relates to an electronic device comprising atleast one photoactive layer positioned between two electrical contactlayers, wherein the at least one layer of the device includes theiridium complex of the invention. Devices frequently have additionalhole transport and electron transport layers. A typical structure isshown in FIG. 1. The device 100 has an anode layer 110 and a cathodelayer 150. Adjacent to the anode is a layer 120 comprising holetransport material. Adjacent to the cathode is a layer 140 comprising anelectron transport material. Between the hole transport layer and theelectron transport layer is the photoactive layer 130. Layers 120, 130,and 140 are individually and collectively referred to as the activelayers.

Depending upon the application of the device 100, the photoactive layer130 can be a light-emitting layer that is activated by an appliedvoltage (such as in a light-emitting diode or light-emittingelectrochemical cell), a layer of material that responds to radiantenergy and generates a signal with or without an applied bias voltage(such as in a photodetector). Examples of photodetectors includephotoconductive cells, photoresistors, photoswitches, phototransistors,and phototubes, and photovoltaic cells, as these terms are describe inMarkus, John, Electronics and Nucleonics Dictionary, 470 and 476(McGraw-Hill, Inc. 1966).

The iridium compounds of the invention are particularly useful as thephotoactive material in layer 130, or as electron transport material inlayer 140. Preferably the iridium complexes of the invention are used asthe light-emitting material in diodes. It has been found that in theseapplications, the compounds of the invention do not need to be in asolid matrix diluent in order to be effective. A layer that is greaterthan 20% by weight iridium compound, based on the total weight of thelayer, up to 100% iridium compound, can be used as the emitting layer.Additional materials can be present in the emitting layer with theiridium compound. For example, a fluorescent dye may be present to alterthe color of emission. A diluent may also be added. The diluent can be apolymeric material, such as poly(N-vinyl carbazole) and polysilane. Itcan also be a small molecule, such as 4,4′-N,N′-dicarbazole biphenyl ortertiary aromatic amines. When a diluent is used, the iridium compoundis generally present in a small amount, usually less than 20% by weight,preferably less than 10% by weight, based on the total weight of thelayer.

In some cases the iridium complexes may be present in more than oneisomeric form, or mixtures of different complexes may be present. Itwill be understood that in the above discussion of OLEDs, the term “theiridium compound” is intended to encompass mixtures of compounds and/orisomers.

To achieve a high efficiency LED, the HOMO (highest occupied molecularorbital) of the hole transport material should align with the workfunction of the anode, the LUMO (lowest un-occupied molecular orbital)of the electron transport material should align with the work functionof the cathode. Chemical compatibility and sublimation temp of thematerials are also important considerations in selecting the electronand hole transport materials.

The other layers in the OLED can be made of any materials which areknown to be useful in such layers. The anode 110, is an electrode thatis particularly efficient for injecting positive charge carriers. It canbe made of, for example materials containing a metal, mixed metal,alloy, metal oxide or mixed-metal oxide, or it can be a conductingpolymer. Suitable metals include the Group 11 metals, the metals inGroups 4, 5, and 6, and the Group 8-10 transition metals. If the anodeis to be light-transmitting, mixed-metal oxides of Groups 12, 13 and 14metals, such as indium-tin-oxide, are generally used. The anode 110 mayalso comprise an organic material such as polyaniline as described in“Flexible light-emitting diodes made from soluble conducting polymer,”Nature vol. 357, pp 477–479 (11 Jun. 1992). At least one of the anodeand cathode should be at least partially transparent to allow thegenerated light to be observed.

Examples of hole transport materials for layer 120 have been summarizedfor example, in Kirk-Othmer Encyclopedia of Chemical Technology, FourthEdition, Vol. 18, p. 837–860, 1996, by Y. Wang. Both hole transportingmolecules and polymers can be used. Commonly used hole transportingmolecules are:N,N′-diphenyl-N,N′-bis(3-methylphenyl)-[1,1′-biphenyl]4,4′-diamine(“TPD”), 1,1-bis[(di-4-tolylamino) phenyl]cyclohexane (“TAPC”),N,N′-bis(4-methylphenyl)-N,N′-bis(4-ethylphenyl)-[1,1′-(3,3′-dimethyl)biphenyl]-4,4′-diamine(“ETPD”), tetrakis-(3-methylphenyl)-N,N,N′,N′-2,5-phenylenediamine(“PDA”), a-phenyl-4-N,N-diphenylaminostyrene (“TPS”),p-(diethylamino)-benzaldehyde diphenylhydrazone (“DEH”), triphenylamine(“TPA”), bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)methane(“MPMP”),1-phenyl-3-[p-(diethylamino)styryl]-5-[p-(diethylamino)phenyl]pyrazoline(“PPR” or “DEASP”), 1,2-trans-bis(9H-carbazol-9-yl)cyclobutane (“DCZB”),N,N,N′,N′-tetrakis(4-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (“TTB”),and porphyrinic compounds, such as copper phthalocyanine. Commonly usedhole transporting polymers are polyvinylcarbazole,(phenylmethyl)polysilane, and polyaniline. It is also possible to obtainhole transporting polymers by doping hole transporting molecules such asthose mentioned above into polymers such as polystyrene andpolycarbonate.

Examples of electron transport materials for layer 140 include metalchelated oxinoid compounds, such as tris(8-hydroxyquinolato)aluminum(“Alq₃”); phenanthroline-based compounds, such as2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (“DDPA”) or4,7-diphenyl-1,10-phenanthroline (“DPA”), and azole compounds such as2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole (“PBD”) and3-(4-biphenylyl)-4-phenyl-5-(4-t-butylphenyl)-1,2,4-triazole (“TAZ”).Layer 140 can function both to facilitate electron transport, and alsoserve as a buffer layer or confinement layer to prevent quenching of theexciton at layer interfaces. Preferably, this layer promotes electronmobility and reduces exciton quenching.

The cathode 150, is an electrode that is particularly efficient forinjecting electrons or negative charge carriers. The cathode can be anymetal or nonmetal having a lower work function than the anode. Materialsfor the cathode can be selected from alkali metals of Group 1 (e.g., Li,Cs), the Group 2 (alkaline earth) metals, the Group 12 metals, includingthe rare earth elements and lanthanides, and the actinides. Materialssuch as aluminum, indium, calcium, barium, samarium and magnesium, aswell as combinations, can be used. Li-containing organometalliccompounds can also be deposited between the organic layer and thecathode layer to lower the operating voltage.

It is known to have other layers in organic electronic devices. Forexample, there can be a layer (not shown) between the conductive polymerlayer 120 and the active layer 130 to facilitate positive chargetransport and/or band-gap matching of the layers, or to function as aprotective layer. Similarly, there can be additional layers (not shown)between the active layer 130 and the cathode layer 150 to facilitatenegative charge transport and/or band-gap matching between the layers,or to function as a protective layer. Layers that are known in the artcan be used. In addition, any of the above-described layers can be madeof two or more layers. Alternatively, some or all of inorganic anodelayer 110, the conductive polymer layer 120, the active layer 130, andcathode layer 150, may be surface treated to increase charge carriertransport efficiency. The choice of materials for each of the componentlayers is preferably determined by balancing the goals of providing adevice with high device efficiency.

It is understood that each functional layer may be made up of more thanone layer.

The device can be prepared by sequentially vapor depositing theindividual layers on a suitable substrate. Substrates such as glass andpolymeric films can be used. Conventional vapor deposition techniquescan be used, such as thermal evaporation, chemical vapor deposition, andthe like. Alternatively, the organic layers can be coated from solutionsor dispersions in suitable solvents, using any conventional coatingtechnique. In general, the different layers will have the followingrange of thicknesses: anode 110, 500–5000 Å, preferably 1000–2000 Å;hole transport layer 120, 50–1000 Å, preferably 200–800 Å;light-emitting layer 130, 10–1000 Å, preferably 100–800 Å; electrontransport layer 140, 50–1000 Å, preferably 200–800 Å; cathode 150,200–10000 Å, preferably 300–5000 Å. The location of the electron-holerecombination zone in the device, and thus the emission spectrum of thedevice, can be affected by the relative thickness of each layer. Thusthe thickness of the electron-transport layer should be chosen so thatthe electron-hole recombination zone is in the light-emitting layer. Thedesired ratio of layer thicknesses will depend on the exact nature ofthe materials used.

It is understood that the efficiency of devices made with the iridiumcompounds of the invention, can be further improved by optimizing theother layers in the device. For example, more efficient cathodes such asCa, Ba or LiF can be used. Shaped substrates and novel hole transportmaterials that result in a reduction in operating voltage or increasequantum efficiency are also applicable. Additional layers can also beadded to tailor the energy levels of the various layers and facilitateelectroluminescence.

The iridium complexes of the invention are phosphorescent andphotoluminescent and may be useful in applications other than OLEDs. Forexample, organometallic complexes of iridium have been used as oxygensensitive indicators, as phosphorescent indicators in bioassays, and ascatalysts.

EXAMPLES

The following examples illustrate certain features and advantages of thepresent invention. They are intended to be illustrative of theinvention, but not limiting. All percentages are by weight, unlessotherwise indicated.

Example 1

This example illustrates the preparation of the 2-phenylpyridines and2-phenylpyrimidines which are used to form the iridium compounds.

The general procedure used was described in O. Lohse, P. Thevenin, E.Waldvogel Synlett, 1999, 45–48. In a typical experiment, a mixture of200 ml of degassed water, 20 g of potassium carbonate, 150 ml of1,2-dimethoxyethane, 0.5 g of Pd(PPh₃)₄, 0.05 mol of a substituted2-chloropyridine (quinoline or pyrimidine) and 0.05 mol of a substitutedphenylboronic acid was refluxed (80–90° C.) for 16–30 h. The resultingreaction mixture was diluted with 300 ml of water and extracted withCH₂Cl₂ (2×100 ml). The combined organic layers were dried over MgSO₄,and the solvent removed by vacuum. The liquid products were purified byfractional vacuum distillation. The solid materials were recrystallizedfrom hexane. The typical purity of isolated materials was >98%.

2-(2′,4′-dimethoxyphenyl)pyridine was prepared via Kumada coupling of2-chloropyridine with 2,4-dimethoxyphenylmagnesium bromide in thepresence of [(dppb)PdCl₂] catalyst, where dppb represents1,4-bis(diphenylphosphino)butane).

The starting materials, yields, melting and boiling points of the newmaterials are given in Table 3. NMR data and analytical data are givenin Table 4.

TABLE 3 Preparation of 2-Phenyl Pyridines, Phenylpyrimidines andPhenylquinolines Compound Yield in % B.p./mm Hg (m.p.) in ° C. 1-s 70 —1-a 72 — 1-b 48 — 1-u 75 (76–78) 1-c 41 (95–96) 1-d 38 (39–40) 1-e 5574.5/0.1 1-g 86 71–73/0.07 1-t 65 77–78/0.046 1-k 50 (38–40) 1-m 8072–73/0.01 1-f 22 52–33/0.12 1-v 63 95–96/13 1-w 72 1-x 35 61–62/0.0951-y 62 (68–70) 1-z 42 66–67/0.06 (58–60) 1-aa 60 1-ab 61.5 70–72/0.031-ac 39 66–68/0.01 1-ad 76 75–76/0.01(54–56) 1-ae 76 69–70/0.06(44–46)1-af 84 (83–85) 1-ag 72 64–65/0.026 1-ah 36 62/0.01 1-ai 49 99–101/0.261-aj 58 108–109/0.1 1-ak 46 76–77/01(52–54)

TABLE 4 Properties of 2-Phenyl Pyridines, Phenylpyrimidines andPhenylquinolines Analysis %, found(calc.) Compound ¹H NMR ¹⁹F NMR orMS(M⁺) 1-s 7.48(3H), −62.68 C, 64.50(64.57) 7.70(1H), H, 3.49(3.59)7.83(1H), N, 6.07(6.28) 7.90(2H), 8.75(1H) 1-a 7.19(1H), −60.82(3F, s),C, 59.56(59.75) 7.30(1H), −116.96(1F, m) H, 3.19(2.90) 7.43(1H), N,5.52(5.81) 7.98(2H), 8.07(1H) 9.00(1H) 1-b 7.58(1H), −62.75(3F, s), C,53.68(53.60) 7.66(1H), −63.10(3F, s) H, 2.61(2.40) 7.88(1H), N,4.53(4.81) 8.03(1H), 8.23(1H), 8.35(1H) 8.99(1H) 1-u 7.55(1H), −62.89(s)C, 69.17(70.33) 7.63(1H), H, 3.79(3.66) 7.75(2H), N, 4.88(5.12)7.89(2H), 8.28(2H), 8.38(1H), 8.50(1H) 1-c 7.53(1H), −62.14(s) C,53.83(53.73) 7.64(1H), H, 2.89(2.61) 7.90(1H), N, 9.99(10.44) 8.18(1H),8.30(1H), 8.53(1H), 9.43(1H) 1-d 7.06(1H), −62.78(3F, s), C,59.73(59.75) 7.48(1H), −112.61(1F, m) H, 2.86(2.90) 7.81(3H), N,5.70(5.81) 8.01(1H), 8.95(1H), 1-e 3.80(3H) −62.63(s) C, 61.66(61.90)6.93(2H), H, 3.95(4.04) 7.68(1H), N, 5.53(5.38) 7.85(1H), 7.96(2H),8.82(1H), 1-g 2.70(3H) −114.03(m) C, 76.56(77.00) 7.10(3H), H,5.12(5.30) 7.48(1H), N, 5.43(7.50) 7.60(1H), 8.05(2H), 1-t 7.10(2H),−62.73(3F, s) C, 50.51(52.17) 7.35(2H), −113.67(1F, m) H, 1.97(2.17)7.96(1H), N, 5.09(5.07) 8.78(1H), 1-k 7.08(2H), −62.75(3F, s) C,60.39(59.75), 7.62(1H), −111.49(m) H, 3.38(2.90), 7.90(3H), N,5.53(5.51) 8.80(1H), 1-m 7.10(2H), −62.63(3F, s) C, 52.13(52.17)7.80(2H), −111.24(m) H, 2.16(2.17) 8.00(1H), N, 4.85(5.07) 8.75(1H), 1-f7.55(3H), −62.57(s) 257(M⁺, 7.77(2H), C₁₂H₇F₃CIN⁺), 8.06(1H), 222(M-Cl)8.87(1H) 1-v 3.8(3H), −62.70 ppm C, 61.66(61.37), 6.95(1H), H,3.98(3.67), 7.30(1H), N, 5.53(5.48) 7.50(1H), 7.58(1H), 7.75(1H),7.90(1H), 8.87(1H) 1-w 8.54(1H, −63.08(3F, s) d), 8.21(2H, d), 7.70(2H,d), 7.24(1H, s), 6.82(1H, dd), 3.91(3H, s) 1-x 6.9(2H, m), −109.70(1F,m), 7.18(2H, −113.35(1F, m). m), 7.68(2H, m), 7.95(1H, m), 8.65(1H, m);1-y 6.94(1H), −62.72(3F, s), 7.62(2H), −109.11(2F, m) 7.82(1H),8.03(1H), 8.96(1H); 1-z 6.85(1H), −62.80(3F, s), 6.93(1H), −107.65(1F,m), 7.80, 7.90, −112.45(1F, m). 8.05(3H), 8.89(1H); 1-aa 7.70(3H, m),7.85(3H, m), 7.80, 7.90, 8.85(1H, m). 1-ab 2.39(3H), −102.96(1F, m),6.99(2H), −113.18(1F, m) 7.02(1H), 7.57(1H), 7.99(1H) 8.56(1H) 1-ac2.47(3H), −63.23(s) 7.17(1H), 7.63(1H), 7.91(1H), 8.48(2H), 8.60(1H),9.00(1H) 1-ad 2.25(3H), −110.37(1F, m) 6.90(2H), −113.50(1F, m)7.55(2H), 8.50(1H), 8.85(1H), 1-ae 2.35(3H), −63.03(s) 7.05(1H),7.55(2H), 8.01(1H), 8.18(1H), 8.50(1H) 1-af 2.43(3H) −63.18(s) 7.66(1H),7.87(1H), 8.47(2H), 8.59(1H) 1-ag 7.20(1H), −63.05(s) 7.65(3H),8.10(1H), 8.17(1H), 8.65(1H), 9.43(1H) 1-ah 6.90(1H), −109.70(1F, m)7.18(2H), −113.35(1F, m) 7.68(2H), 7.95(1H), 8.65(1H), 1-aj 1.35(9H)−63.19 7.34(1H) 7.72(1H) 7.88(1H) 8.44(2H) 8.61(1H) 1-ak 2.46(3H) −62.867.15(1H) 7.60(1H) 7.73(2H) 8.11(2H) 8.59(1H)Compound 1-al has been reported previously in the literature.

Examples 2–4

These examples illustrate the preparation of the phosphinoalkanolprecursor compounds.

Example 2

This example illustrates the preparation of the precursor compound1;1-bis(trifluoromethyl)-2-bis(triphenylphosphino)-ethanol (PO-1H). Thecompound was made by two different methods.

Method A:

The phosphino alkanol was made according to the procedure in Inorg.Chem. (1985), 24(22), pp. 3680–7. Under nitrogen,1,1-bis(trifluoromethyl)ethylene oxide (12 g, 0.066 mol) was addeddropwise to a pre-cooled (10–15° C.) solution of diphenylphosphine (10g, 0.053 mol) in dry THF (50 mL). The reaction mixture was stirred at25° C. for 2 days, after which NMR analysis indicated >90% conversion.The solvent was removed under vacuum and the residual viscous oil wasdistilled under vacuum to give 8 g of the fraction (b.p. 110–114° C. at0.05 mm Hg) which crystallized on standing. Both the NMR data and m.p.(59–62° C.) of this material (>95% purity) were consistent with thosereported in: Boere, R. T. et al., Inorg. Chem. (1985), 24, 3680. ¹H NMR(CDCl₃, 20° C.), δ: 7.3–7.8 (m, 10H, arom. H); 2.8 (br. s.; 1H, OH); 2.2(s, 2H, CH₂). ¹⁹F NMR (CDCl₃, 20° C.), δ: −77.3 (d, J_(F-P)=15.5 Hz).³¹P NMR (CDCl₃, 20° C.), δ: −24.4 (septet, J_(P-F)=15.5 Hz).

Method B:

(i) Preparation of 1,1-bis(trifluoromethyl)-2-bromoethanol,BrCH₂C(CF₃)₂OH. 1,1-bis(trifluoromethyl)oxirane (100 g; 0.55 mol;prepared as described in WO 00/66575, 2000, to DuPont). was added slowlyto 100 ml of 47% aqueous HBr placed in a round bottom glass flaskequipped with a dry-ice condenser, thermometer, and magnetic stir bar at30–40° C. The reaction mixture was stirred under reflux for 3 h. At thatpoint the temperature raised to 90° C. After cooling to roomtemperature, the bottom layer was separated, dried over MgSO₄, anddistilled to give 104 g (72%) of BrCH₂C(CF₃)₂OH, b.p. 101–103° C. ¹H NMR(CDCl₃): 3.50 (br s, 1H, —OH), 3.70(s, 2H, CH₂). ¹⁹F NMR (CDCl₃): −75.9(s). This material was dried over freshly calcined molecular sieves (4Å) prior to the next step.

(ii) Under nitrogen, to a stirring solution of1,1-bis(trifluoromethyl)-2-bromoethanol (5.64 g; prepared as describedabove) in dry ether (110 mL) cooled to −78° C., was added drop-wise 1.6M n-BuLi in hexanes (Aldrich; 27 mL). After 1 h at −78° C.,chlorodiphenylphosphine (Strem; 4.53 g) was added drop-wise, at vigorousstirring, to the resulting solution of the dilithiated derivative. Afterstirring the mixture for 3 h 20 min at −78° C., it was allowed to warmslowly to room temperature and then stirred at room temperatureovernight. The solvents were removed under vacuum. Dichloromethane (10mL) and trifluoroacetic acid (1.66 mL) were added to the residue, andthe mixture was chromatographed on a silica gel column (5×25 cm) withdichloromethane. The product was isolated as an oil which crystallizedupon drying under vacuum. The yield of the product as white crystallinesolid was 5.3 g (71%). The compound was found identical with thematerial synthesized according to method a.

1,1-bis(trifluoromethyl)-2-bis(triphenylphosphino)-ethoxide [PO-1]

To make the sodium salt of the ethoxide ligand PO-1, sodium hydride wasadded to the alcohol in THF. The salt was isolated by removing thevolatile components in vacuo.

Example 3

This example illustrates the preparation of the phosphinoalkanolprecursor compound Ar₂PCH₂C(OH)(CF₃)₂, where Ar=3,5-(CF₃)₂C₆H₃ [PO-2H].

Method A:

Under nitrogen, a stirring solution of (3,5-(CF₃)₂C₆H₃)₂PH (1.50 g; 3.27mmol; prepared as described in: Casey, C. P. et al., J. Am. Chem. Soc.(1997), 119, 11817) in THF (30 mL) was cooled to −78° C. and treatedwith a 1.6 M solution of n-BuLi in hexanes (2.06 mL; 3.30 mmol) toproduce a deep-purple reaction mixture. To the latter was added, atstirring, 1,1-bis(trifluoromethyl)ethylene oxide (0.59 g; 0.453 mL; 3.27mmol) and the mixture was allowed to warm to room temperature. Afterstirring at room temperature overnight, the solution was treated with0.3 mL of trifluoroacetic acid and evaporated to dryness.Flash-chromatography (silica gel, methylene chloride-hexanes 50:50 byvolume) of the residue, followed by vacuum sublimation producedAr₂PCH₂C(OH)(CF₃)₂ (1.52 g; 73%; slightly contaminated with thecorresponding phosphine oxide). Anal. Calcd for C₂₀H₉F₁₈OP, %: C, 37.6;H, 1.4. Found, %: C, 37.5; H, 1.4. ¹H NMR (CD₂Cl₂, 20° C.), δ: 8.0 (m,6H, arom. H); 3.9 (br. s.; 1H, OH); 2.9 (s, 2H, CH₂). ¹⁹F NMR (CD₂Cl₂,20° C.), δ: −63.9 (s, 12F, (CF₃)₂C₆H₃); −77.8 (d, J_(F-P)=19.4 Hz, 6F,(CF₃)₂COH). ³¹P NMR (CD₂Cl₂, 20° C.), δ: −22.1 (septet, J_(P-F)=19.4Hz).

Method B:

Under nitrogen, to a stirring solution of1,1-bis(trifluoromethyl)-2-bromoethanol (0.91 g) in dry ether (20 mL)cooled to −78° C., was added drop-wise 1.6 M n-BuLi in hexanes (Aldrich;4.35 mL). After 1 h at −78° C., (3,5-(CF₃)₂C₆H₃)₂PCl (1.63 g; preparedas described in: Casalnuovo et al., U.S. Pat. No. 5,175,335) was addeddrop-wise, at vigorous stirring, to the resulting solution of thedilithiated derivative. After stirring for 2 h at −78° C., the mixturewas allowed to warm slowly to room temperature and then stirred at roomtemperature overnight. The solvents were removed under vacuum.Dichloromethane (5 mL) and trifluoroacetic acid (0.26 mL) were added tothe residue. Flash-chromatography (silica gel, dichloromethane) of themixture produced solid Ar₂PCH₂C(OH)(CF₃)₂ (1.32 g; 62%) which was foundto be identical to the material synthesized according to method b.

Example 4

This example illustrates the preparation of the phosphinoalkanolprecursor compound, Ar₂PCH₂C(OH)(CF₃)₂, where Ar=4-CF₃C₆H₄ (PO-3H).

Under nitrogen, to a stirring solution of1,1-bis(trifluoromethyl)-2-bromoethanol (2.28 g) in dry ether (46 mL)cooled to −78° C., was added drop-wise 1.6 M n-BuLi in hexanes (Aldrich;10.93 mL). After 1 h at −78° C., (4-CF₃C₆H₄)₂PCl (3.28 g; prepared asdescribed in: Casalnuovo et al., J. Am. Chem. Soc., 1994, 116, 9869) wasadded drop-wise, at vigorous stirring, to the resulting solution of thedilithiated derivative. After stirring for 2 h at −78° C., the mixturewas allowed to warm slowly to room temperature and then stirred at roomtemperature overnight. The solvents were removed under vacuum.Dichloromethane (7 mL) and trifluoroacetic acid (0.64 mL) were added tothe residue. Flash-chromatography (silica gel, dichloromethane) of themixture, followed by solvent evaporation and vacuum-drying producedAr₂PCH₂C(OH)(CF₃)₂ (3.36 g; 81%) as a slightly yellow oil.). Anal. Calcdfor C₁₈H₁₁F₁₂OP, %: C, 43.0; H, 2.2. Found, %: C, 42.8; H, 2.2. ¹H NMR(CD₂Cl₂, 20° C.), δ: 7.7 (m, 8H, arom. H); 3.6 (br. s.; 1H, OH); 2.9 (s,2H, CH₂). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −63.5 (s, 6F, CF₃C₆H₄); −77.6 (d,J_(F-P)=18.6 Hz, 6F, (CF₃)₂COH). ³¹P NMR (CD₂Cl₂, 20° C.), δ: −27.1(septet, J_(P-F)=18.6 Hz).

Example 5

This example illustrates the preparation of the phosphinoalkanolprecursor compound, Ar₂PCH₂C(OH)(CF₃)₂, where Ar═C₆F₅ (PO-4H).

Under nitrogen, to a stirring solution of1,1-bis(trifluoromethyl)-2-bromoethanol (3.43 g) in dry ether (70 mL)cooled to −78° C., was added drop-wise 1.6 M n-BuLi in hexanes (Aldrich;16.43 mL). After 30 min at −78° C., (C₆F₅)₂PCl (5.0 g; prepared asdescribed in: RajanBabu et al., J. Org. Chem., 1999, 64, 3429) was addeddrop-wise, at vigorous stirring, to the resulting solution of thedilithiated derivative. After stirring for 5.5 h at −78° C., the mixturewas allowed to warm slowly to room temperature and then stirred at roomtemperature overnight. The solvents were removed under vacuum.Dichloromethane (10 mL) and trifluoroacetic acid (0.96 mL) were added tothe residue. Flash-chromatography (silica gel, dichloromethane) of themixture, followed by solvent evaporation and vacuum-drying producedAr₂PCH₂C(OH)(CF₃)₂ (1.58 g; 23%) as a white solid. Anal. Calcd forC₁₆H₃F₁₆OP, %: C, 35.2; H, 0.55. Found, %: C, 35.1; H, 0.05. ¹H NMR(CD₂Cl₂, 20° C.), δ: 3.3 (s, 2H, CH₂); 3.6 (br. s.; 1H, OH). ¹⁹F NMR(CD₂Cl₂, 20° C.), δ: −77.8 (d, J_(F-P)=20.5 Hz, 6F, CF₃); −130.6 (m, 4F,o-C₆F₅); −150.0 (t, J_(F-F)=20 Hz; 2F, p-C₆F₅); −161.0 (m, 4F, m-C₆F₅).³¹P NMR (CD₂Cl₂, 20° C.), δ: −57.6 (m).

Example 6

This example illustrates the formation of dichloro-bridged dinuclearbis-cyclometallated Ir complexes.

The Ir complexes were prepared by the reaction between IrCl₃.nH₂O andthe corresponding 2-arylpyridine in aqueous 2-ethoxyethanol. The methodis similar to the literatures procedure for 2-phenylpyridine (Sprouse,S.; King, K. A.; Spellane, P. J.; Watts, R. J., J. Am. Chem. Soc., 1984,106, 6647–53; Garces, F. O.; King, K. A.; Watts, R. J., Inorg. Chem.,1988, 27, 3464–71.). A mixture of IrCl₃.nH₂O, a 2-arylpyridine (2.2–2.8equivalents per Ir), 2-ethoxyethanol (ca. 30 mL per 1 g of IrCl₃.nH₂O),and water (ca. 5 mL per 30 mL of 2-ethoxyethanol) was vigorously stirredunder reflux (N₂) for 4–10 hours. After cooling to room temperature,conc. HCl (3 mL per 1 g IrCl₃.nH₂O) was added, and the mixture wasstirred for 30 min. The mixture was diluted with water, stirred for 1–2hours, and filtered. The solid product was washed with water, methanol,and dried under vacuum. The yields ranged from 65 to 99%.

Example 7

This example illustrates the formation of Ir complexes of the inventionhaving the Formula I.

Dicyclometalated Arylpyridine Iridium (III) Mononuclear ComplexesContaining Phosphinoalkanol Ligands.

The general procedure was to combine a dichloro-bridged dinuclearbis-cyclometallated Ir complex from Example 6, a phosphinoalkanolcompound (1.1–1.5 equivs per Ir), 1,2-dichloroethane (DCE; 3–12 mL), and10% aqueous NaOH (2–10-fold excess) and stir under reflux (N₂) until allsolids dissolved and then for additional 0.5–1.5 hours. The productswere isolated and purified in air. The organic layer was separated,filtered through a short silica gel plug, and reduced in volume to 0.5–2mL. Treatment of the residue with hexanes resulted in crystallization(1–3 h) of the desired product which was separated, washed with hexanes,and dried under vacuum. X-ray analysis of three complexes (2-b, 2-g,2-j, and 2-u) indicated trans arrangement of the nitrogen atoms. ³¹PNMR=³¹P—{¹H} NMR.

Compound 2-a (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ab from Example 1 (150 mg),phosphinoalkanol PO-1H from Example 2 (100 mg), DCE (3 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 1 h. The yelloworganic layer (blue photoluminescent) was separated and filtered througha short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to 1–2 mL and treated with hexanes (10mL; portionwise). The lemon-yellow crystals were separated, washed withhexanes (3×5 mL), and dried under vacuum. Yield: 0.22 g (97%). Anal.Calcd for C₄₀H₂₈F₁₀N₂IrOP.C₂H₄Cl₂, %: C, 47.4; H, 3.0; N, 2.6. Found, %:C, 47.5; H, 3.1; N, 2.5. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.5 (s, 3H, CH₃);2.51 (s, 3H, CH₃); 3.0 (dd, J_(H-H)=16.2 Hz, J_(H-P)=9.1 Hz, 1H, CH₂);3.6 (dd, J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz, 1H, CH₂); 3.8 (s, solventC₂H₄Cl₂), 5.5 (m, 1H, arom H); 6.1 (m, 1H, arom H); 6.5 (m, 2H, arom H);6.65 (m, 1H, arom H); 6.7 (m, 3H, arom H); 7.0 (m, 2H, arom H); 7.1 (m,1H, arom H); 7.4 (m, 3H, arom H); 7.6 (m, 3H, arom H); 8.0 (s, 1H, aromH); 8.2 (s, 1H, arom H); 8.3 (d, 1H, arom H); 8.7 (d, 1H, arom H). ¹⁹FNMR (CD₂Cl₂, 20° C.), δ: −75.1 (m, 3F, CF₃); −78.8 (m, 3F, CF₃); −109.2(m, 1F, arom F); −109.9 (m, 1F, arom F); −110.4 (m, 1F, arom F); −111.0(m, 1F, arom F). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 10.2 (s).

Compound 2-b (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ab from Example 1 (200 mg),phosphinoalkanol PO-2H from Example 3 (270 mg), DCE (6 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 25 min. The yelloworganic layer (blue photoluminescent) was separated and filtered througha short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to 1–2 mL and treated with hexanes (10mL; portionwise). The lemon-yellow crystals were separated, washed withhexanes (3×5 mL), and dried under vacuum. Yield: 0.38 g (97%). Anal.Calcd for C₄₄H₂₄F₂₂N₂IrOP, %: C, 42.7; H, 1.9; N, 2.3. Found, %: C,42.5; H, 1.9; N, 2.3. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.5 (s, 3H, CH₃); 2.51(s, 3H, CH₃); 3.1 (dd, J_(H-H)=16.2 Hz, J_(H-P)=8.3 Hz, 1H, CH₂); 3.8(dd, J_(H-H)=16.2 Hz, J_(H-P)=12.5 Hz, 1H, CH₂); 5.4 (m, 1H, arom H);6.1 (m, 1H, arom H); 6.6 (m, 2H, arom H); 6.7 (m, 1H, arom H); 6.9 (m,1H, arom H); 7.25 (m, 2H, arom H); 7.7 (s, 1H, arom H); 8.1 (m, 5H, aromH); 8.25 (m, 1H, arom H); 8.7 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.),δ: −63.8 (s, 6F, arom CF₃); −64.1 (s, 6F, arom CF₃); −75.0 (m, 3F,HOCCF₃); −79.1 (m, 3F, HOCCF₃); −107.6 (m, 1F, arom F); −108.1 (m, 1F,arom F); −109.7 (m, 2F, arom F). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 14.6 (s).The structure was confirmed by X-ray analysis.

Compound 2-c (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ah from Example 1 (200 mg),phosphinoalkanol PO-1H from Example 2 (150 mg), DCE (5 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 0.5 h. The yelloworganic layer (blue photoluminescent) was separated and filtered througha short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to 1–2 mL and treated with hexanes (10mL; portionwise). The lemon-yellow crystals were separated, washed withhexanes (3×5 mL), and dried under vacuum. Yield: 0.29 g (94%). Anal.Calcd for C₃₈H₂₄F₁₀N₂IrOP, %: C, 48.7; H, 2.6; N, 3.0. Found, %: C,49.1; H, 2.7; N, 2.8. ¹H NMR (CD₂Cl₂, 20° C.), δ: 3.05 (dd, J_(H-H)=16.2Hz, J_(H-P)=9.1 Hz, 1H, CH₂); 3.6 (dd, J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz,1H, CH₂); 5.4 (m, 1H, arom H); 6.1 (m, 1H, arom H); 6.5 (m, 2H, arom H);7.0 (m, 8H, arom H); 7.5 (m, 6H, arom H); 7.7 (t, 1H, arom H); 7.7.8 (t,1H, arom H); 8.15 (d, 1H, arom H); 8.3 (dd, 1H, arom H); 8.5 (d, 1H,arom H); 8.9 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −75.0 (m, 3F,CF₃); −78.9 (m, 3F, CF₃); −108.6 (m, 1F, arom F); −109.2 (m, 1F, aromF); −110.3 (m, 1F, arom F); −110.9 (m, 1F, arom F). ³¹P NMR (CD₂Cl₂, 20°C.), δ: 10.4(s).

Compound 2-d (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ah from Example 1 (150 mg),phosphinoalkanol PO-2H from Example 3 (190 mg), DCE (5 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 20 min. The yelloworganic layer (blue photoluminescent) was separated and filtered througha short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to 1–2 mL and treated with hexanes (5mL). The lemon-yellow needle-shaped crystals were separated, washed withhexanes (3×5 mL), and dried under vacuum. Yield: 0.255 g (85%). Anal.Calcd for C₄₂H₂₀F₂₂N₂IrOP, %: C, 41.7; H, 1.7; N, 2.3. Found, %: C,41.7; H, 1.2; N, 2.4. ¹H NMR (CD₂Cl₂, 20° C.), δ: 3.1 (dd, J_(H-H)=16.6Hz, J_(H-P)=8.3 Hz, 1H, CH₂); 3.8 (dd, J_(H-H)=16.6 Hz, J_(H-P)=12.4 Hz,1H, CH₂); 5.45 (m, 1H, arom H); 6.15 (m, 1H, arom H); 6.6 (m, 2H, aromH); 6.9 (t, 1H, arom H); 7.0 (t, 1H, arom H); 7.25 (d, 2H, arom H); 7.7(m, 2H, arom H); 7.9 (t, 1H, arom H); 8.1 (m, 2H, arom H); 8.2 (d, 1H,arom H); 8.25 (d, 1H, arom H); 8.4 (dd, 2H, arom H); 8.9 (d, 1H, aromH). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −63.7 (s, 6F, arom CF₃); −64.0 (s, 6F,arom CF₃); −75.0 (m, 3F, HOCCF₃); −79.1 (m, 3F, HOCCF₃); −106.9 (m, 1F,arom F); −107.4 (m, 1F, arom F); −109.5 (m, 2F, arom F). ³¹P NMR(CD₂Cl₂, 20° C.), δ: 14.6 (s).

Compound 2-e (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ag from Example 1 (110 mg),phosphinoalkanol PO-1H from Example 2 (85 mg), DCE (3 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 0.5 h. The yelloworganic layer (blue photoluminescent) was separated and filtered througha short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to ca. 0.5 mL and treated with hexanes(5 mL; portionwise). The lemon-yellow crystals were separated, washedwith hexanes (3×5 mL), and dried under vacuum. Yield: 0.17 g (99%).Anal. Calcd for C₄₀H₂₆F₁₂N₂IrOP.1/2C₂H₄Cl₂, %: C, 46.8; H, 2.7; N, 2.7.Found, %: C, 46.4; H, 2.7; N, 2.4. ¹H NMR (CD₂Cl₂, 20° C.), δ: 3.05 (dd,J_(H-H)=16. 2 Hz, J_(H-P)=8.7 Hz, 1H, CH₂); 3.65 (dd, J_(H-H)=16.2 Hz,J_(H-P)=11.7 Hz, 1H, CH₂); 3.8 (s, solvent C₂H₄Cl₂), 6.1 (m, 1H, aromH); 7.0 (m, 10H, arom H); 7.4 (m, 3H, arom H); 7.5 (m, 2H, arom H); 7.7(m, 1H, arom H); 7.9 (m, 5H, arom H); 8.5 (d, 1H, arom H); 9.0 (d, 1H,arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −62.4 (s, 3F, arom CF₃); −62.7 (s,3F, arom CF₃); −75.1 (m, 3F, CF₃); −79.0 (m, 3F, CF₃). ³¹P NMR (CD₂Cl₂,20° C.), δ: 10.6 (s).

Compound 2-f (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ac from Example 1 (350 mg),phosphinoalkanol PO-1H from Example 2 (205 mg), DCE (4 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 30 min. The reactionmixture was extracted with dichloromethane and the combined organicextracts were filtered through a short silica gel plug, then reduced involume to ca. 1 mL and treated with hexanes (10 mL). After 1 h the palegreenish-yellow crystals (blue-photoluminescent) were separated, washedwith hexanes, and dried under vacuum. Yield: 0.44 g (90%). Anal. Calcdfor C₄₄H₂₈F₁₈N₂IrOP, %: C, 45.3; H, 2.4; N, 2.4. Found, %: C, 45.0; H,2.2; N, 2.3. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.35 (s, 3H, CH₃); 2.5 (s, 3H,CH₃); 2.9 (dd, J_(H-H)=16.5 Hz, J_(H-P)=10.2 Hz, 1H, CH₂); 3.3 (dd,J_(H-H)=16.5 Hz, J_(H-P)=12.1 Hz, 1H, CH₂); 6.5 (d, 1H, arom H); 6.7 (m,2H, arom H); 6.8 (d, 1H, arom H); 7.0 (m, 2H, arom H); 7.2 (m, 4H, aromH); 7.4 (m, 2H, arom H); 7.5 (m, 1H, arom H); 7.6 (s, 1H, arom H); 7.75(s, 1H, arom H); 7.9 (d, 2H, arom H); 8.2 (m, 2H, arom H); 8.65 (d, 1H,arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −58.2 (s, 3F, arom CF₃); −59.8 (s,3F, arom CF₃); −59.8 (s, 3F, arom CF₃); −62.7 (s, 3F, arom CF₃); −63.0(s, 3F, arom CF₃); −73.5 (m, 3F, HOCCF₃); −79.2 (m, 3F, HOCCF₃). ³¹P NMR(CD₂Cl₂, 20° C.), δ: 11.4 (s).

Compound 2-g (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ac from Example 1 (200 mg),phosphinoalkanol PO-2H from Example 3 (190 mg), DCE (5 mL), and 10% NaOH(0.7 mL) was vigorously stirred under reflux (N₂) for 15 min. Thereaction mixture was extracted with dichloromethane and the combinedorganic extracts were filtered through a silica gel column, then reducedin volume to ca. 2–3 mL and treated with hexanes (10 mL). Thepale-yellow crystals (blue-photoluminescent) were separated, washed withhexanes (3×5 mL), and dried under vacuum. Yield: 0.30 g (87%). Anal.Calcd for C₄₈H₂₄F₃₀N₂IrOP, %: C, 40.1; H, 1.7; N, 2.0. Found, %: C,40.1; H, 1.2; N, 2.1. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.35 (s, 3H, CH₃);2.55 (s, 3H, CH₃); 2.95 (dd, J_(H-H)=16.6 Hz, J_(H-P)=9.5 Hz, 1H, CH₂);3.6 (dd, J_(H-H)=16.6 Hz, J_(H-P)=12.5 Hz, 1H, CH₂); 6.6 (d, 1H, aromH); 6.8 (d, 1H, arom H); 7.2 (d, 2H, arom H); 7.3 (s, 1H, arom H); 7.6(m, 3H, arom H); 7.8 (s, 1H, arom H); 7.9 (m, 3H, arom H); 8.1 (s, 2H,arom H); 8.2 (s, 1H, arom H); 8.6 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20°C.), δ: −58.3 (s, 3F, arom CF₃); −60.1 (s, 3F, arom CF₃); −63.1 (s, 3F,arom CF₃); −63.6 (s, 3F, arom CF₃); −63.9 (s, 6F, arom CF₃); −64.2 (s,6F, arom CF₃); −73.0 (m, 3F, HOCCF₃); −79.7 (m, 3F, HOCCF₃). ³¹P NMR(CD₂Cl₂, 20° C.), δ: 13.7 (s). The structure was confirmed by X-rayanalysis.

Compound 2-h (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ad from Example 1 (430 mg),phosphinoalkanol PO-1H from Example 2 (310 mg), DCE (10 mL), and 10%NaOH (1 mL) was vigorously stirred under reflux (N₂) for 1 h. The yelloworganic layer (blue photoluminescent) was separated and filtered througha short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to 1–2 mL and treated with hexanes (10mL; portionwise). The lemon-yellow crystals were separated,recrystallized from boiling toluene, washed with hexanes (3×5 mL), anddried under vacuum. Yield: 0.45 g (65%). Anal. Calcd for C₄₇H₃₆F₁₀N₂IrOP(1:1 toluene solvate), %: C, 53.4; H, 3.4; N, 2.7. Found, %: C, 53.2; H,3.1; N, 2.7. ¹H NMR (CD₂Cl₂, 20° C.), δ: 1.9 (s, 3H, CH₃); 2.2 (s, 3H,CH₃); 2.4 (s, solvent toluene); 3.0 (dd, J_(H-H)=16.2 Hz, J_(H-P)=9.0Hz, 1H, CH₂); 3.6 (dd, J_(H-H)=16.2 Hz, J_(H-P)=11.7 Hz, 1H, CH₂); 5.5(m, 1H, arom H); 6.1 (m, 1H, arom H); 6.5 (m, 2H, arom H); 6.7 (m, 2H,arom H); 7.0 (m, 2H, arom H); 7.2 (m, 4H, arom H); 7.5 (m, 8H, arom H);8.05 (d, 1H, arom H); 8.2 (dd, 1H, arom H); 8.3 (s, 1H, arom H); 8.85(s, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −75.0 (m, 3F, CF₃); −79.0(m, 3F, CF₃); −109.5 (m, 1F, arom F); −110.2 (m, 1F, arom F); −111.4 (m,1F, arom F); −111.8 (m, 1F, arom F). ³¹P NMR (CD₂Cl₂, 20° C.),6:11.2(s).

Compound 2-i (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ad from Example 1 (200 mg),phosphinoalkanol PO-2H from Example 3 (240 mg), DCE (6 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 1 h 10 min. Theyellow organic layer (blue photoluminescent) was separated and filteredthrough a short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to 2 mL and treated with hexanes (10mL). After 1 hour, the pale-yellow crystals were separated, washed withhexanes (3×5 mL), and dried under vacuum. Yield: 0.31 g (80%). Anal.Calcd for C₄₄H₂₄F₂₂N₂IrOP, %: C, 42.7; H, 1.9; N, 2.3. Found, %: C,42.5; H, 1.4; N, 2.4. ¹H NMR (CD₂Cl₂, 20° C.), δ: 1.9 (s, 3H, CH₃); 2.2(s, 3H, CH₃); 3.1 (dd, J_(H-H)=16.2 Hz, J_(H-P)=8.7 Hz, 1H, CH₂); 3.75(dd, J_(H-H)=16.2 Hz, J_(H-P)=12.5 Hz, 1H, CH₂); 5.4 (m, 1H, arom H);6.1 (m, 1H, arom H); 6.6 (m, 2H, arom H); 7.2 (d, 2H, arom H); 7.5 (d,1H, arom H); 7.7 (m, 2H, arom H); 8.1 (m, 5H, arom H); 8.3 (dd, 1H, aromH); 8.7 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −63.8 (s, 6F, aromCF₃); −63.9 (s, 6F, arom CF₃); −75.0 (m, 3F, HOCCF₃); −79.1 (m, 3F,HOCCF₃); −107.9 (m, 1F, arom F); −108.3 (m, 1F, arom F); −110.3 (m, 1F,arom F); −110.6 (m, 1F, arom F). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 14.6(s).

Compound 2-j (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-k (340 mg) from Example 1,phosphinoalkanol PO-1H from Example 2 (220 mg), DCE (5 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 20 min. The yelloworganic layer (green photoluminescent) was separated and filteredthrough a short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to ca. 1 mL and treated with hexanes(10 mL). The yellow oil solidified upon trituration. The solid wasrecrystallized from dichloromethane-hexanes, washed with hexanes (3×5mL), and dried under vacuum. Yield: 0.45 g (90%). The structure wasconfirmed by X-ray analysis (1:1 hydrate with H₂O hydrogen-bonded to theO atom of the complex). ¹H NMR (CD₂Cl₂, 20° C.), δ: 3.0 (dd,J_(H-H)=16.6 Hz, J_(H-P)=9.1 Hz, 1H, CH₂); 3.6 (dd, J_(H-H)=16.2 Hz,J_(H-P)=12.1 Hz, 1H, CH₂); 3.8 (s, solvent C₂H₄Cl₂), 5.5 (m, 1H, aromH); 5.6 (m, 1H, arom H); 6.4 (m, 1H, arom H); 6.7 (m, 4H, arom H); 7.0(m, 2H, arom H); 7.1 (m, 1H, arom H); 7.4 (m, 3H, arom H); 7.5 (m, 2H,arom H); 7.7 (m, 4H, arom H); 8.0 (m, 2H, arom H); 8.8 (s, 1H, arom H);9.2 (s, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −63.3 (br m, 3F, aromCF₃); −63.5 (s, 3F, arom CF₃); −75.5 (m, 3F, CF₃); −78.9 (m, 3F, CF₃);−108.0 (m, 1F, arom F); −108.5 (m, 1F, arom F). 31P NMR (CD₂Cl₂, 20°C.), 6:12.2 (s).

Compound 2-k (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ai from Example 1 (300 mg),phosphinoalkanol PO-1H from Example 2 (215 mg), DCE (5 mL), and 10% NaOH(2 mL) was vigorously stirred under reflux (N₂) for 2 h. The yelloworganic layer (blue photoluminescent) was separated and filtered througha short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were evaporated to dryness and treated with hexanes (10 mL).The yellow oil (blue-photoluminescent) dissolved upon heating themixture after a few hours at room temperature yellow solid formed. Theproduct was washed with hexanes (3×5 mL), and dried under vacuum. Yield:0.22 g (50%). Anal. Calcd for C₄₆H₄₀F₁₀N₂IrOP, %: C, 52.6; H, 3.8; N,2.7. Found, %: C, 53.5; H, 3.8; N, 2.8. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.5(s, 3H, CH₃); 2.51 (s, 3H, CH₃); 3.0 (dd, J_(H-H)=16.2 Hz, J_(H-P)=9.1Hz, 1H, CH₂); 3.6 (dd, J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz, 1H, CH₂); 3.8(s, solvent C₂H₄Cl₂), 5.5 (m, 1H, arom H); 6.1 (m, 1H, arom H); 6.5 (m,2H, arom H); 6.65 (m, 1H, arom H); 6.7 (m, 3H, arom H); 7.0 (m, 2H, aromH); 7.1 (m, 1H, arom H); 7.4 (m, 3H, arom H); 7.6 (m, 3H, arom H); 8.0(s, 1H, arom H); 8.2 (s, 1H, arom H); 8.3 (d, 1H, arom H); 8.7 (d, 1H,arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −75.0 (m, 3F, CF₃); −79.0 (m, 3F,CF₃); −109.3 (m, 1F, arom F); −110.0 (m, 1F, arom F); −110.7 (m, 1F,arom F); −111.3 (m, 1F, arom F). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 10.2 (s).

Compound 2-l (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-aj from Example 1 (217 mg),phosphinoalkanol PO-1H from Example 2 (100 mg), DCE (4 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 10 min. The yelloworganic layer (blue-green photoluminescent) was separated and filteredthrough a short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were evaporated to ca. 1 mL, treated with hexanes (5 mL), andleft at room temperature overnight. The yellow crystals(blue-green-photoluminescent) were washed with hexanes (3×2 mL), anddried under vacuum. Yield: 0.195 g (66%). Anal. Calcd forC₅₀H₄₀F₁₈N₂IrOP, %: C, 48.0; H, 3.2; N, 2.2. Found, %: C, 47.6; H, 3.0;N, 2.1. ¹H NMR (CD₂Cl₂, 20° C.), δ: 1.3 (s, 9H, t-Bu); 1.4 (s, 9H, CH₃);2.9 (dd, J_(H-H)=16.2 Hz, J_(H-P)=10.2 Hz, 1H, CH₂); 3.3 (dd,J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz, 1H, CH₂); 6.6 (dd, 1H, arom H); 6.8(m, 2H, arom H); 7.0 (m, 3H, arom H); 7.2 (m, 3H, arom H); 7.4 (m, 4H,arom H); 7.6 (s, 1H, arom H); 7.8 (s, 1H, arom H); 8.0 (m, 2H, arom H);8.2 (s, 1H, arom H); 8.3 (m, 1H, arom H); 8.7 (d, 1H, arom H). ¹⁹F NMR(CD₂Cl₂, 20° C.), δ: −58.4 (s, 3F, arom CF₃); −59.8 (s, 3F, arom CF₃);−62.4 (s, 3F, arom CF₃); −62.6 (s, 3F, arom CF₃); −73.2 (m, 3F, aliphCF₃); −79.2 (m, 3F, aliph CF₃). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 9.8 (s).

Compound 2-m (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ad from Example 1 (150 mg),phosphinoalkanol PO-3H from Example 4 (140 mg), DCE (5 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 1 h 30 min. Theyellow organic layer (blue photoluminescent) was separated and filteredthrough a short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to 2 mL and treated with hexanes (10mL). The pale-yellow crystals were recrystallized fromdichloromethane-hexanes, washed with hexanes (3×5 mL), and dried undervacuum. Yield: 0.23 g (88%). Anal. Calcd for C₄₂H₂₆F₁₆N₂IrOP, %: C,45.8; H, 2.4; N, 2.5. Found, %: C, 45.2; H, 2.2; N, 2.4. ¹H NMR (CD₂Cl₂,20° C.), δ: 1.9 (s, 3H, CH₃); 2.2 (s, 3H, CH₃); 3.1 (dd, J_(H-H)=16.2Hz, J_(H-P)=9.1 Hz, 1H, CH₂); 3.6 (dd, J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz,1H, CH₂); 5.5 (m, 1H, arom H); 6.1 (m, 1H, arom H); 6.5 (m, 2H, arom H);6.9 (m, 2H, arom H); 7.3 (d, 2H, arom H); 7.7 (m, 6H, arom H); 8.0 (m,1H, arom H); 8.2 (m, 1H, arom H); 8.8 (s, 1H, arom H). ¹⁹F NMR (CD₂Cl₂,20° C.), δ: −63.9 (s, 3F, arom CF₃); −64.0 (s, 3F, arom CF₃); −75.0 (m,3F, HOCCF₃); −79.0 (m, 3F, HOCCF₃); −108.9 (m, 1F, arom F); −109.2 (m,1F, arom F); −111.0 (m, 1F, arom F); −111.1 (m, 1F, arom F). ³¹P NMR(CD₂Cl₂, 20° C.), δ: 13.1 (s).

Compound 2-n (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ab from Example 1 (60 mg),phosphinoalkanol PO-3H from Example 4 (60 mg), DCE (3 mL), and 10% NaOH(0.5 mL) was vigorously stirred under reflux (N₂) for 30 min. Thereaction mixture was extracted with dichloromethane and the combinedorganic extracts were filtered through a silica gel column, then reducedin volume to ca. 0.5 mL and treated with hexanes (4 mL). The pale-yellowcrystals (blue-photoluminescent) were separated, washed with hexanes(3×1 mL), and dried under vacuum. Yield: 0.085 g (82%). Anal. Calcd forC₄₂H₂₆F₁₆N₂IrOP, %: C, 45.8; H, 2.4; N, 2.5. Found, %: C, 46.4; H, 2.2;N, 2.3. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.35 (s, 3H, CH₃); 2.55 (s, 3H,CH₃); 2.95 (dd, J_(H-H)=16.6 Hz, J_(H-P)=9.5 Hz, 1H, CH₂); 3.6 (dd,J_(H-H)=16.6 Hz, J_(H-P)=12.5 Hz, 1H, CH₂); 6.6 (d, 1H, arom H); 6.8 (d,1H, arom H); 7.2 (d, 2H, arom H); 7.3 (s, 1H, arom H); 7.6 (m, 3H, aromH); 7.8 (s, 1H, arom H); 7.9 (m, 3H, arom H); 8.1 (s, 2H, arom H); 8.2(s, 1H, arom H); 8.6 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −63.9(s, 3F, arom CF₃); −64.0 (s, 3F, arom CF₃); −75.1 (m, 3F, HOCCF₃); −78.8(m, 3F, HOCCF₃); ³¹P NMR (CD₂Cl₂, 20° C.), δ: 12.7 (s).

Compound 2-o (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-al from Example 1 (170 mg),phosphinoalkanol PO-1H from Example 2 (140 mg), DCE (3 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 20 min. The yelloworganic layer (green photoluminescent) was separated and filteredthrough a short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to ca. 0.5 mL and treated with hexanes(10 mL, portionwise). The yellow crystals were separated, washed withhexanes (3×5 mL), and dried under vacuum. Yield: 0.25 g (92%). Anal.Calcd for C₄₄H₃₆F₆N₂IrO₅P.1/2C₂H₄Cl, %: C, 51.0; H, 3.6; N, 2.6. Found,%: C, 50.7; H, 3.7; N, 2.7. ¹H NMR (CD₂Cl₂, 20° C.), δ: 3.0 (dd,J_(H-H)=16.2 Hz, J_(H-P)=8.7 Hz, 1H, CH₂); 3.4 (s, 3H, CH₃O); 3.55 (s,3H, CH₃O); 3.6 (dd, J_(H-H)=16.2 Hz, J_(H-P)=11.3 Hz, 1H, CH₂); 3.95 (s,3H, CH₃O); 4.0 (s, 3H, CH₃O); 5.05 (m, 1H, arom H); 5.7 (m, 1H, arom H);6.2 (m, 2H, arom H); 6.6 (m, 1H, arom H); 6.8 (m, 3H, arom H); 6.95 (m,2H, arom H); 7.05 (m, 1H, arom H); 7.4 (m, 3H, arom H); 7.6 (m, 4H, aromH); 8.4 (d, 1H, arom H); 8.6 (d, 1H, arom H); 8.7 (d, 1H, arom H); 8.9(d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −75.1 (m, 3F, HOCCF₃);−79.0 (m, 3F, HOCCF₃). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 8.5 (s).

Compound 2-p (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-al from Example 1 (110 mg),phosphinoalkanol PO-2H from Example 3 (125 mg), DCE (3 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 20 min. The yelloworganic layer (bluish-green photoluminescent) was separated and filteredthrough a short silica plug. The aqueous layer was extracted withdichloromethane and passed through the same plug. The combined organicsolutions were reduced in volume to ca. 0.5 mL and treated with hexanes(4 mL). The yellow crystals were separated, washed with hexanes (3×5mL), and dried under vacuum. Yield: 0.18 g (85%). Anal. Calcd forC₄₆H₃₂F₁₈N₂IrO₅P, %: C, 43.9; H, 2.6; N, 2.2. Found, %: C, 43.8; H, 2.1;N, 2.4. ¹H NMR (CD₂Cl₂, 20° C.), δ: 3.1 (dd, J_(H-H)=16.2 Hz,J_(H-P)=9.1 Hz, 1H, CH₂); 3.4 (s, 3H, CH₃O); 3.55 (s, 3H, CH₃O); 3.7(dd, J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz, 1H, CH₂); 3.95 (s, 3H, CH₃O); 4.0(s, 3H, CH₃O); 5.15 (m, 1H, arom H); 5.75 (m, 1H, arom H); 6.2 (m, 2H,arom H); 6.7 (m, 1H, arom H); 6.8 (m, 1H, arom H); 7.25 (d, 2H, arom H);7.5 (t, 1H, arom H); 7.65 (s, 1H, arom H); 7.7 (t, 1H, arom H); 8.0 (s,1H, arom H); 8.1 (d, 2H, arom H); 8.25 (d, 1H, arom H); 8.45 (d, 1H,arom H); 8.75 (d, 1H, arom H); 8.85 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂,20° C.), δ: −63.7 (s, 6F, arom CF₃); −64.0 (s, 6F, arom CF₃); −75.1 (m,3F, HOCCF₃); −78.9 (m, 3F, HOCCF₃). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 14.6(s).

Compound 2-q (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ae from Example 1 (520 mg),phosphinoalkanol PO-1H from Example 2 (340 mg), DCE (5 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 30 min. The reactionmixture was extracted with toluene and then dichloromethane and thecombined organic extracts were filtered through a short silica gel plug,then reduced in volume to ca. 3 mL and treated with hexanes (20 mL).After 1 h the yellow crystals (blue-green photoluminescent) wereseparated, washed with hexanes, and dried under vacuum. Yield: 0.755 g(92%). Anal. Calcd for C_(45.5)H₃₄F₁₂N₂IrOP (crystallized with ½molecule of toluene), %: C, 50.8; H, 3.2; N, 2.6. Found, %: C, 50.8; H,3.1; N, 2.6. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.55 (s, 3H, CH₃); 2.6 (s, 3H,CH₃); 3.0 (dd, J_(H-H)=16.2 Hz, J_(H-P)=8.7 Hz, 1H, CH₂); 3.6 (dd,J_(H-H)=16.2 Hz, J_(H-P)=11.7 Hz, 1H, CH₂); 6.1 (m, 1H, arom H); 6.7 (m,4H, arom H); 6.9 (m, 1H, arom H); 7.0 (m, 2H, arom H); 7.1 (m, 3H, aromH); 7.2 (m, 1H, arom H); 7.5 (m, 3H, arom H); 7.6 (m, 2H, arom H); 7.7(s, 1H, arom H); 7.8 (s, 1H, arom H); 7.9 (s, 1H, arom H); 7.95 (s, 1H,arom H); 8.3 (d, 1H, arom H); 8.75 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20°C.), δ: −62.2 (s, 3F, arom CF₃); −62.8 (s, 3F, arom CF₃); −75.2 (m, 3F,HOCCF₃); −78.9 (m, 3F, HOCCF₃). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 10.3 (s).

Compound 2-r (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ae from Example 1 (200 mg),phosphinoalkanol PO-2H from Example 3 (230 mg), DCE (5 mL), and 10% NaOH(1 mL) was vigorously stirred under reflux (N₂) for 10 min. The reactionmixture was extracted with dichloromethane and the combined organicextracts were filtered through a silica gel column, then reduced involume to ca. 1–2 mL and treated with hexanes (7 mL). After 3 hours thepale-yellow crystals (blue-photoluminescent) were separated, washed withhexanes (3×3 mL), and dried under vacuum. Yield: 0.34 g (90%). Anal.Calcd for C₄₆H₂₆F₂₄N₂IrOP, %: C, 42.4; H, 2.0; N, 2.2. Found, %: C,42.2; H, 1.4; N, 2.3. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.3 (s, 3H, CH₃); 2.6(s, 3H, CH₃); 3.1 (dd, J_(H-H)=16.2 Hz, J_(H-P)=8.3 Hz, 1H, CH₂); 3.8(dd, J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz, 1H, CH₂); 6.1 (m, 1H, arom H);6.7 (m, 2H, arom H); 7.0 (d, 1H, arom H); 7.1 (d, 1H, arom H); 7.2 (m,3H, arom H); 7.7 (m, 2H, arom H); 7.9 (m, 3H, arom H); 8.1 (m, 4H, aromH); 8.7 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −62.9 (s, 3F, aromCF₃); −63.0 (s, 3F, arom CF₃); −63.6 (s, 3F, arom CF₃); −63.9 (s, 3F,arom CF₃); −75.1 (m, 3F, HOCCF₃); −79.1 (m, 3F, HOCCF₃). ³¹P NMR(CD₂Cl₂, 20° C.), δ: 14.6 (s).

Compound 2-s (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ak from Example 1 (220 mg),phosphinoalkanol PO-1H from Example 2 (140 mg), DCE (4 mL), and 10% NaOH(0.5 mL) was vigorously stirred under reflux (N₂) for 25 min. Thereaction mixture was extracted with dichloromethane and the combinedorganic extracts were filtered through a silica gel column, then reducedin volume to ca. 1 mL and treated with hexanes (8 mL). After 1 hour atroom temperature and then 30 min at +5° C. the pale-yellow crystals(green-photoluminescent) were separated, washed with hexanes (3×1 mL),and dried under vacuum. Yield: 0.30 g (94%). Anal. Calcd forC₄₂H₃₀F₁₂N₂IrOP, %: C, 49.0; H, 2.9; N, 2.7. Found, %: C, 49.0; H, 2.8;N, 2.5. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.55 (s, 3H, CH₃); 2.6 (s, 3H, CH₃);3.0 (dd, J_(H-H)=16.2 Hz, J_(H-P)=8.7 Hz, 1H, CH₂); 3.6 (dd,J_(H-H)=16.2 Hz, J_(H-P)=12.1 Hz, 1H, CH₂); 6.2 (m, 1H, arom H); 6.7 (m,3H, arom H); 7.0 (m, 4H, arom H); 7.1 (m, 1H, arom H); 7.4 (m, 7H, aromH); 7.7 (m, 4H, arom H); 8.3 (d, 1H, arom H); 8.8 (d, 1H, arom H). ¹⁹FNMR (CD₂Cl₂, 20° C.), δ: −63.3 (s, 6F, arom CF₃); −75.1 (m, 3F, HOCCF₃);−79.0 (m, 3F, HOCCF₃). ³¹P NMR (CD₂Cl₂, 20° C.), δ: 9.0 (s).

Compound 2-t (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ac from Example 1 (160 mg),phosphinoalkanol PO-4H from Example 5 (120 mg), DCE (4 mL), and 10% NaOH(0.2 mL) was vigorously stirred under reflux (N₂) for 10 min. Thereaction mixture was extracted with dichloromethane and the combinedorganic extracts were filtered through a silica gel column, then reducedin volume to ca. 1 mL and treated with hexanes (8 mL). The yellowprecipitate was recrystallized from dichlorometane (warm)-hexanes,washed with hexanes (3×1 mL), and dried under vacuum. Yield: 0.222 g(86%). Anal. Calcd for C₄₄H₁₈F₂₈N₂IrOP, %: C, 39.3; H, 1.3; N, 2.1.Found, %: C, 39.4; H, 1.2; N, 2.0. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.5 (s,3H, CH₃); 2.6 (s, 3H, CH₃); 2.7 (dd, J_(H-H)=17.0 Hz, J_(H-P)=8.7 Hz,1H, CH₂); 4.3 (dd, J_(H-H)=17.0 Hz, J_(H-P)=ca. 17.0 Hz, 1H, CH₂); 6.8(m, 2H, arom H); 7.6 (s, 1H, arom H); 7.65 (s, 1H, arom H); 7.7 (s, 1H,arom H); 7.9 (s, 1H, arom H); 8.0 (s, 1H, arom H); 8.2 (m, 2H, arom H);8.7 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −57.9 (s, 3F, aromCF₃); −59.5 (br s, 3F, arom CF₃); −62.8 (s, 3F, arom CF₃); −63.0 (s, 3F,arom CF₃); −74.6 (m, 3F, HOCCF₃); −78.7 (m, 3F, HOCCF₃); −124.2 (br s,2F, C₆F₅); ca. −128 (very br s, 2F, C₆F₅); −144.5 (m, 1F, C₆F₅); −147.7(m, 1F, C₆F₅); −157.7 (br s, 2F, C₆F₅); −159.8 (br s, 2F, C₆F₅). ³¹P NMR(CD₂Cl₂, 20° C.), δ: −13.4 (br s).

Compound 2-u (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with phenylpyridine compound 1-ab from Example 1 (100 mg),phosphinoalkanol PO-4H from Example 5 (98 mg), DCE (4 mL), and 10% NaOH(0.2 mL) was vigorously stirred under reflux (N₂) for 15 min. Thereaction mixture was extracted with dichloromethane and the combinedorganic extracts were filtered through a silica gel column, thenevaporated to dryness. The yellow residue was recrystallized fromdichlorometane-hexanes, washed with hexanes (3×1 mL), and dried undervacuum. Yield of the product (1:1 dichloromethane solvate): 0.135 g(70%). Anal. Calcd for C₄₁H₂₀F₂₀N₂IrOPCl₂, %: C, 40.0; H, 1.6; N, 2.3.Found, %: C, 40.1; H, 1.5; N, 2.2. ¹H NMR (CD₂Cl₂, 20° C.), δ: 2.5 (s,3H, CH₃); 2.6 (s, 3H, CH₃); 2.7 (dd, J_(H-H)=17.0 Hz, J_(H-P)=8.7 Hz,1H, CH₂); 4.3 (dd, J_(H-H)=17.0 Hz, J_(H-P)=ca. 17.0 Hz, 1H, CH₂); 6.8(m, 2H, arom H); 7.6 (s, 1H, arom H); 7.65 (s, 1H, arom H); 7.7 (s, 1H,arom H); 7.9 (s, 1H, arom H); 8.0 (s, 1H, arom H); 8.2 (m, 2H, arom H);8.7 (d, 1H, arom H). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −76.9 (m, 3F, CF₃);−78.4 (m, 3F, CF₃); −108.0 (m, 1F, arom F); −109.7 (m, 1F, arom F);−109.8 (m, 1F, arom F); −111.8 (m, 1F, arom F); −124.6 (br s, 2F, C₆F₅);ca. −129 (very br s, 2F, C₆F₅); −145.5 (m, 1F, C₆F₅); −148.8 (m, 1F,C₆F₅); −158.3 (m, 2F, C₆F₅); −160.5 (br s, 2F, C₆F₅). ³¹NMR (CD₂Cl₂, 20°C.), δ: −5.3 (br s). The structure/composition was confirmed by X-rayanalysis.

Compound 2-v (Table 2)

A mixture of the dichloro-bridged dinuclear bis-cyclometallated Ircomplex made with 2-phenylpyridine, prepared as described in Sprouse,S.; King, K. A.; Spellane, P. J.; Watts, R. J., J. Am. Chem. Soc., 1984,106, 6647–53; Garces, F. O.; King, K. A.; Watts, R. J., Inorg. Chem.,1988, 27, 3464–71 (120 mg), phosphinoalkanol PO-2H from Example 3 (170mg), DCE (4 mL), and 10% NaOH (1 mL) was vigorously stirred under reflux(N₂) for 20 min. The reaction mixture was extracted with dichloromethaneand the combined organic extracts were filtered through a silica gelcolumn, then evaporated to 1–2 mL and treated with hexanes (8 mL,portionwise). After 4 hours the yellow precipitate was separated andrecrystallized from dichlorometane-hexanes, washed with hexanes (3×1mL), and dried under vacuum. Yield: 0.22 g (86%). Anal. Calcd forC₄₂H₂₄F₁₈N₂IrOP, %: C, 44.3; H, 2.1; N, 2.5. Found, %: C, 43.9; H, 1.6;N, 2.6. ¹H NMR (CD₂Cl₂, 20° C.), δ: 3.1 (dd, J_(H-H)=16.2 Hz,J_(H-P)=8.3 Hz, 1H, CH₂); 3.8 (dd, J_(H-H)=16.2 Hz, J_(H-P)=ca. 12.1 Hz,1H, CH₂); 6.0 (m, 1H, arom H); 6.7 (m, 1H, arom H); 6.9 (m, 2H, arom H);7.0 (m, 4H, arom H); 7.2 (m, 2H, arom H); 7.7 (m, 6H, arom H); 7.9 (m,2H, arom H); 8.1 (m, 2H, arom H); 8.3 (d, 1H, arom H); 8.9 (d, 1H, aromH). ¹⁹F NMR (CD₂Cl₂, 20° C.), δ: −63.5 (s, 6F, arom CF₃); −63.8 (s, 6F,arom CF₃); −75.2 (m, 3F, CF₃COH); −79.1 (m, 3F, CF₃COH). ³¹P NMR(CD₂Cl₂, 20° C.), δ: 14.0 (s).

Example 8

This example illustrates the formation of an Ir complex of the inventionhaving the Formula I, in a two-step, one-pot method, directly from IrCl₃(hydrate).

Compound 2-f (Table 2)

A mixture of IrCl₃ (hydrate; ca. 54% Ir), arylpyridine 1-ac (12.00 g;86% purity, contained 14% of 2-chloro-4-methylpyridine startingmaterial), 2-ethoxyethanol (100 mL), and water (20 mL) was stirred underreflux for 2 hours. The solid-free yellow-tan solution was cooled toabout 100° C., treated, at stirring, with a solution of NaOH (3.0 g) inwater (20 mL) (the mixture turned dark), and then immediately withphosphinoalkanol PO-1H from Example 2 (6.0 g). The mixture turned yellowand a yellow precipitate formed. Water (100 mL) was added, and themixture was stirred for 5 min at 110° C. (oil bath). The mixture wasallowed to cool to room temperature and then kept at ca. 10° C.overnight. The solid was separated by filtration, washed with water,dried on the filter, and dissolved in ca. 400 mL of warmdichloromethane. The solution was filtered through a silica gel columnwhich was then washed with dichloromethane. The combined organicsolutions were reduced in volume to ca. 20–30 mL and treated withhexanes (150 mL). After 2 hours the crystalline pale-yellow precipitatewas separated, washed with hexanes (4×20 mL), and dried under vacuum.Yield of 2-f: 12.3 g (calculated on Ir). The product was found to beTLC- and spectroscopically pure (¹H, ¹⁹F, and ³¹P NMR; see Example 7).

Example 9

This example illustrates the formation of OLEDs using the iridiumcomplexes of the invention.

Thin film OLED devices including a hole transport layer (HT layer),electroluminescent layer (EL layer) and at least one electron transportlayer (ET layer) were fabricated by the thermal evaporation technique.An Edward Auto 306 evaporator with oil diffusion pump was used. The basevacuum for all of the thin film deposition was in the range of 10⁻⁶torr. The deposition chamber was capable of depositing five differentfilms without the need to break up the vacuum.

An indium tin oxide (ITO) coated glass substrate was used, having an ITOlayer of about 1000–2000 Å. The substrate was first patterned by etchingaway the unwanted ITO area with 1N HCl solution, to form a firstelectrode pattern. Polyimide tape was used as the mask. The patternedITO substrates were then cleaned ultrasonically in aqueous detergentsolution. The substrates were then rinsed with distilled water, followedby isopropanol, and then degreased in toluene vapor for ˜3 hours.

The cleaned, patterned ITO substrate was then loaded into the vacuumchamber and the chamber was pumped down to 10⁻⁶ torr. The substrate wasthen further cleaned using an oxygen plasma for about 5–10 minutes.After cleaning, multiple layers of thin films were then depositedsequentially onto the substrate by thermal evaporation. Finally,patterned metal electrodes of Al were deposited through a mask. Thethickness of the film was measured during deposition using a quartzcrystal monitor (Sycon STC-200). All film thickness reported in theExamples are nominal, calculated assuming the density of the materialdeposited to be one. The completed OLED device was then taken out of thevacuum chamber and characterized immediately without encapsulation.

A summary of the device layers and thicknesses is given in Table 5. Inall cases the anode was ITO as discussed above, and the cathode was Alhaving a thickness in the range of 700–760 Å.

TABLE 5 HT layer (Thickness, EL layer ET layer Sample Å) (Thickness, Å)(Thickness, Å) 9-1 MPMP Compound 2-a DPA (538) (404) (408) 9-2 MPMPCompound 2-a DPA (511) (411) (410) 9-3 MPMP Compound 2-c DPA (575) (412)(402) 9-4 MPMP Compound 2-d DPA (511) (411) (411) 9-5 MPMP Compound 2-eDPA (535) (423) (412) 9-6 MPMP Compound 2-f DPA (526) (436) (404) 9-7MPMP Compound 2-g DPA (505) (433) (408) 9-8 MPMP Compound 2-h DPA (544)(424) (412) 9-9 MPMP Compound 2-i DPA (548) (438) (725) 9-10 MPMPCompound 2-k DPA (510) (404) (414) 9-11 MPMP Compound 2-o DPA (504)(422) (387) 9-12 MPMP Compound 2-p DPA (512) (408) (402) 9-13 MPMPCompound 2-q DPA (546) (428) (411) 9-14 MPMP Compound 2-r DPA (516)(462) (408) 9-15 MPMP Compound 2-s DPA (508) (461) (412) 9-16 MPMPCompound 2-v DPA (514) (406) (407) MPMP =bis[4-(N,N-diethylamino)-2-methylphenyl](4-methylphenyl)-methane DPA =4,7-diphenyl-1,10-phenanthrolineThe OLED samples were characterized by measuring their (1)current-voltage (I-V) curves, (2) electroluminescence radiance versusvoltage, and (3) electroluminescence spectra versus voltage. Theapparatus used, 200, is shown in FIG. 7. The I-V curves of an OLEDsample, 220, were measured with a Keithley Source-Measurement Unit Model237, 280. The electroluminescence radiance (in the unit of Cd/m²) vs.voltage was measured with a Minolta LS-110 luminescence meter, 210,while the voltage was scanned using the Keithley SMU. Theelectroluminescence spectrum was obtained by collecting light using apair of lenses, 230, through an electronic shutter, 240, dispersedthrough a spectrograph, 250, and then measured with a diode arraydetector, 260. All three measurements were performed at the same timeand controlled by a computer, 270. The efficiency of the device atcertain voltage is determined by dividing the electroluminescenceradiance of the LED by the current density needed to run the device. Theunit is in Cd/A. The results are given in Table 6 below:

TABLE 6 Electroluminescent Properties of Iridium Compounds Peak PeakApproximate Peak Radiance, efficiency, Wavelengths, Sample Cd/m2 Cd/A nm9-1 450 4.5 460 and 500 at 23 V 9-2 15 0.6 460 and 490 at 20 V 9-3 4502.8 465 and 495 at 20 V 9-4 35 0.4 460 and 480 at 20 V 9-5 900 5.0 470and 510 at 22 V 9-6 450 12.0 470 and 505 at 21 V 9-7 25 1.0 470 and 500at 23 V 9-8 400 5.5 470 and 500 at 22 V 9-9 190 1.2 465 and 495 at 22 V9-10 880 6.0 463 and 490 at 22 V 9-11 700 4.0 480 and 510 at 21 V 9-12120 0.8 478 and 505 at 20 V 9-13 1500 12.0 470 and 500 at 22 V 9-14 2501.8 468 and 497 at 25 V 9-15 2400 17.0 500 at 22 V 9-16 250 1.5 483 and506 at 22 V

1. A process for preparing a phosphinoalkanol comprising: (1) combining an epoxide with aqueous HBr, to form a bromohydrin; (2) isolating the bromohydrin from step (1) and removing water; (3) combining the dried bromohydrin from step (2) with n-butyl lithium, wherein the molar ratio of n-butyl lithium to bromohydrin is about 2; (4) adding a chlorophosphine to the product of step (3); and (5) adding acid to the product of step (4).
 2. A process for preparing a phosphino alkanol compound comprising the step of combining a dried bromohydrin with n-butyl lithium, wherein the molar ratio of n-butyl lithium to the bromohydrin is about
 2. 3. The process of claim 2 wherein the phospino alkonal compound has Formula III-H, shown in FIG. 2:

wherein: R⁹ can be the same or different at each occurrence and is selected from C_(m)(H+F)_(2n+1), C₆(H+F)_(p)Y_(5−p), R¹⁰ can be the same or different at each occurrence and is selected from H, F, and C_(n)(H+F)_(2n+1); Y is C_(m)(H+F)_(2m+1); n is an integer from 1 through 12; m is 2 or 3; p is 0 or an integer from 1 through
 5. 4. The process of claim 2 wherein said compound is selected from 1-diphenylphosphino-2-propanol; 1,1-bis(trifluoromethyl)-2-(diphenylphosphino)-ethanol; 1,1-bis(trifluoromethyl)-2-(bis(3′5′-ditrifluoromethylphenyl)phosphino)ethanol; 1,1-bis(trifluoromethyl)-2-(bis(4′-trifluoromethylphenyl)phosphino)ethanol; and 1,1-bis(trifluoromethyl)-2-(bis(pentafluorophenyl)phosphino)ethanol. 